Using mail merge to distinguish colours in Word

I'm using a mail merge from Excel. I dont think this is possible but its
worth a try.
I want colours that are listened in excel to be able to represent a colour
of a text box in word.

example.
The title could be "Tree" and in the colour associated in the excel sheet
would be "Green", so in word when the mail merge is run to put "Tree" into a
text box and i would like somehow for word to recognise "green" and then make
that text box background colour green.

Any help would be great, even if its that it's not possible.
Thanks